OBJECTIVE: To develop recombinant isoforms of oviductin and immunological probes to examinine the role of oviductin in mammalian fertilization and early embryogenesis. RESULTS An isoform of oviductin was cloned and inserted into a baculovirus vector used to transform e. coli cells. Plasmid clones were isolated. To form recombinant virus, an insect cell line was transfected with the complete oviductin coding region. A 13 amino acid conserved protein sequence of oviductin was synthesized as a "multiple antigen peptide" and used to produce antisera for further studies. Understanding the natural mechanisms of fertilization is important for conception and contraception. Mammalian sperm and eggs interact in the oviduct which produces factors promoting fertilization at low sperm-egg ratios. The oviductins (estrogen-dependent oviductal glycoproteins) are produced near ovulation and bind to eggs and sperm. Oviductins are implicated in fertilization. FUTURE DIRECTIONS To determine the role of oviductin in fertilization, the molecular specificity of oviductin binding to sperm and eggs, and the role of protein vs. carbohydrate in the binding. Recombinant oviductin will be used to probe the natural function of oviductins. KEY WORDS IVF, sperm, egg, embryo, fallopian tube, oviduct, zona pellucida, estrogen, glycoprotein RR00167; Andrew W. Mellon Foundation; HD22023.